Shopify announced more complete, faster-refreshed shipping and duty data in Analytics. Profit reports using those inputs may change without any change to selling price. Source officielle.
A practical check
Compare a few international orders with actual shipping costs, duties, currency, and values shown in Profit margin by order or Average profit margin by market reports where available.
Example: a report showed a high margin because it did not fully combine duties and shipping on the same order. The newer lower value may be more accurate, even though the store has not lost new sales.
What the evidence supports
A recalculated margin is not necessarily an improved margin. Check uncovered costs and history before changing prices. Date the check and retain the source documentation so that later changes can be verified.